Multimodal Visible-Infrared Subwavelength Structures with Decoupled Modulation of Reflection Spectra.

Visible-infrared reflectivity carries an important part of identity information for most kinds of objects, and its decoupled modulation holds significant application value in the field of identity information reconstruction, such as display, camouflage, and anticounterfeiting. Some well-designed materials or devices have exhibited remarkable abilities in the decoupled modulation of optical reflectivity, but it is difficult to concisely describe their modulation performance as the involved controllable reflectivity characteristics are at least two. Here, a systematic evaluation strategy that comprehensively assesses both the decoupling degree and the changing range through a single quantitative indicator is first proposed, and a set of subwavelength structures is presented for the complex decoupled modulation of four visible-infrared reflectivity characteristics. The decoupled modulation ability of the subwavelength structures is evaluated utilizing the new strategy, where the magnitudes of the indicators align with the modulation flexibility, thus verifying the validity of the proposed evaluation approach. The set of structures possesses robustness and can be fabricated by a controllable electrochemical process. Based on the obtained modulation structures, a multiple identity information display is successfully implemented.